You would use Filter
for this:
with
set [Best Cities in CY 2003/2004] as
filter(
intersect(
topcount(
[Customer].[Customer Geography].[City],
10,
(
[Measures].[Internet Sales Amount],
[Date].[Calendar].[Calendar Year].[CY 2003]
)
),
topcount(
[Customer].[Customer Geography].[City],
10,
(
[Measures].[Internet Sales Amount],
[Date].[Calendar].[Calendar Year].[CY 2004]
)
)
),
([Measures].[Internet Sales Amount], [Date].[Calendar].[Calendar Year].[CY 2004])
/
([Measures].[Internet Sales Amount], [Date].[Calendar].[Calendar Year].[CY 2003])
- 1.0
< -0.35
)
Select [Measures].[Internet Sales Amount] on columns,
[Best Cities in CY 2003/2004] on rows
From [Adventure Works]
Where
{
[Date].[Calendar].[Calendar Year].[CY 2003],
[Date].[Calendar].[Calendar Year].[CY 2004]
}